New motor shaft angular accelerometer concept

Concept permits measurement of the acceleration of continuously rotating shafts without use of slip rings or telemetry and with little additional inertial load. Concept has application in servomotor control circuits and easy-to-fly airplane controls

A new wind energy conversion system

It is presupposed that vertical axis wind energy machines will be superior to horizontal axis machines on a power output/cost basis and the design of a new wind energy machine is presented. The design employs conical cones with sharp lips and smooth surfaces to promote maximum drag and minimize skin friction. The cones are mounted on a vertical axis in such a way as to assist torque development. Storing wind energy as compressed air is thought to be optimal and reasons are: (1) the efficiency of compression is fairly high compared to the conversion of mechanical energy to electrical energy in storage batteries; (2) the release of stored energy through an air motor has high efficiency; and (3) design, construction, and maintenance of an all-mechanical system is usually simpler than for a mechanical to electrical conversion system

Development of computer programs to determine the aerodynamic characteristics of complete light aircraft

A computer program for determining the flight characteristics of light aircraft was developed. The parameters which were used in the computer program are defined. The accuracy of the system for various types of airfoils is analyzed and the airfoils for which the system does not provide adequate data are identified. The application of a computer program for predicting the fuselage characteristics is discussed. The assumptions and parameters of the fuselage characteristics program are explained. It is stated that the computer programs make it possible to determine the response of a light aircraft to a small disturbance given the geometric and inertial characteristics of the aircraft

Mapping individual logical processes in information searching

An interactive dialog with a computerized information collection was recorded and plotted in the form of a flow chart. The process permits one to identify the logical processes employed in considerable detail and is therefore suggested as a tool for measuring individual thought processes in a variety of situations. A sample of an actual test case is given

Prospects and time tables for analytical estimation of the drag of complete aircraft configuration

Analytical drag methods and wind tunnel evaluation of aircraft design features are used to identify excessive drag of general aviation aircraft with reciprocating engines

Results of heating mode performance tests of a solar-assisted heat pump

The performance of a heat pump, utilizing 8.16 square meters of low-cost solar collectors as the evaporator in a Freon-114 refrigeration cycle, was determined under actual insolation conditions during the summer and fall of 1976. C.O.P.'s (coefficient of performance) greater than 3 were obtained with condensing temperatures around 78 C and evaporating temperatures around 27 C. Ambient temperatures were about 3 C above evaporating temperatures. Similar performance levels were obtained at other insolation and temperature conditions. Experience with the system has identified some component and system changes which should increase the obtainable C.O.P. to about 4.0. These are described along with the system's design rationale. The accumulated data are presented as an appendix

Results of an experimental program to provide low cost computer searches of the NASA information file to university graduate students in the southeast Final report

Experimental program to provide low cost computer searches of NASA information files to university graduate student

An economic and performance design study of solar preheaters for domestic hot water heaters in North Carolina

The performance and estimated material costs for several solar preheaters for domestic hot water heaters using isolation levels present in North Carolina are presented. The effects of monthly variations in isolation and the direction of incident radiation are included. Demand is assumed at 13 gallons (49.2 liters) per day per person. The study shows that a closed circulation system with 82 gallons (310 liters) of preheated storage and 53.4 cu ft (4.94 cu m) of collector surface with single cover can be expected to cost about $800 and to repay it capital cost and interest (at 8%) in 5.2 years, assuming present electric rates increase at 5% per year

A study of optimum cowl shapes and flow port locations for minimum drag with effective engine cooling, volume 2

The listings, user's instructions, sample inputs, and sample outputs of two computer programs which are especially useful in obtaining an approximate solution of the viscous flow over an arbitrary nonlifting three dimensional body are provided. The first program performs a potential flow solution by a well known panel method and readjusts this initial solution to account for the effects of the boundary layer displacement thickness, a nonuniform but unidirectional onset flow field, and the presence of air intakes and exhausts. The second program is effectually a geometry package which allows the user to change or refine the shape of a body to satisfy particular needs without a significant amount of human intervention. An effort to reduce the cruise drag of light aircraft through an analytical study of the contributions to the drag arising from the engine cowl shape and the foward fuselage area and also that resulting from the cooling air mass flowing through intake and exhaust sites on the nacelle is presented. The programs may be effectively used to determine the appropriate body modifications or flow port locations to reduce the cruise drag as well as to provide sufficient air flow for cooling the engine

Prediction of light aircraft horizontal tail onset flows: A review and analysis

The theoretical basis of the two computer programs (WASH and WAKE) are developed. WASH calculates the location of wake-sheet streamlines behind the wing, and upwash and downwash angles ahead of and behind the wing, respectively. WAKE computes two-dimensional velocity profiles along the wake streamlines given the upper and lower surface velocity profiles at the wing trailing edge. Comparisons with experiment indicate good agreement for wake location, downwash angles, and two-dimensional velocity profiles at low to moderate angles of attack. The adaptation of the results of the two programs to predict the total onset flow at the tail is discussed